In manufacturing an electronic device, a contact opening may be formed in an interlayer insulation film. In a processing target object having the interlayer insulation film, the interlayer insulation film is formed on a wiring layer, and a mask made of an organic film is provided on the interlayer dielectric film to form an opening. In order to form the opening in the interlayer insulation film of the processing target object, a plasma etching is generally used.
In the plasma etching of the interlayer insulation film, a processing gas containing fluorocarbon is excited in a processing container of a plasma processing apparatus. The insulation film is etched by the active species generated thereby.
Such a plasma etching is disclosed in Japanese Patent Laid-Open Publication No. 2000-311890. In the plasma etching disclosed in Japanese Patent Laid-Open Publication No. 2000-311890, ON and OFF of a high frequency power for exciting the processing gas are periodically switched.